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The following topics are dealt with: laser technology and applications; image processing; optoelectronic devices and integration; and optical communications, medical and biological applications.
To avoid the occasional damages to the quantum cascade lasers (QCLs) which are used in the infrared detection system caused by some poor working conditions, the laser driver circuits are designed and discussed in detail in this paper, which include the constant current and voltage circuit, soft-driver circuit, current limit circuit and short-cut protection circuit. Simulations and experiments prove...
In this work, optical properties from normal and cancerous stroma pairs were measured using reflectance-based confocal microscopy. Our results show that the scattering coefficient of cancerous stroma is significantly lower than that of normal stroma, suggesting that the decreased scattering in cancerous stroma may provide a possible indicator for differentiating normal and cancerous stroma.
The finite-difference time-domain (FDTD) method is employed to analyze the tolerance of the radius of the defected cylinder within periodical dielectric waveguide (PDWG). The optical transmission is very sensitive to the radius of the defected cylinder. It shows that the tolerance of the radius of defected cylinder within PDWG is not good.
It is important to study optical limiting material for laser protection. As a new developing material, carbon nanotubes have exhibit perfect optical limiting property. The experiments are carried out with samples of different solvent and concentration. The results confirm that the optical limiting effect is due to carbon nanotubes and the surfactant is a good solvent to improve the limiting effect...
The coupled microring resonators interference is discussed and applied to intensity sensing. Relaxed from the requirement of high quality factor, better performance of the coupled MR intensity sensor compared with conventional MR sensor is demonstrated by the transfer matrix theory.
The principle of photoelectric joint transform correlator is described and the lack of traditional methods in dealing with target recognition problem under complex background is analyzed. The improved methods are proposed, such as Synthetic Discriminate Function, power subtraction and logarithm filtering. The simulation results show that the optimization improves the recognition ability of the optical...
Triangle algorithm and its modified techniques are used widely in the field of star pattern recognition. However, efficiency and reliability remain key issues. A novel improved triangle algorithm restrained by geometric hull of stars in the field of view, is presented. First, the set of navigation stars in one field of view (FOV) is obtained by three methods. Second, the convex hull is found for the...
This paper describes a high-speed data acquisition and processing system which has been successfully operated on the multi-spectral imagery system. The system, which is based on PCI-E interface, can collect data as 280 MBps and store over 60 minutes per times without losing frames. This study discusses several main problems during hardware design and software design.
A fast photoacoustic topography system based on ring-shaped array transducer as well as a high-speed parallel acquisition equipment was designed and developed for small animal imaging. Samples of point carbon and curly wire embedded in simulated phantom were used to testify the reconstruction algorithm. Tumor angiogenesis on mouse back was successfully depicted in vivo by the system. Experimental...
To ensure traffic security and avoid traffic congestion, accommodation lane is set. A vehicle type measurement device is used to capture the violation drivers. The vehicle type measurement device uses a laser distance sensor with 1.2 KHz pulse repetition and 20 mm accuracy per pulse. The experiment shows that this laser distance sensor can obtain the vehicle profiles to distinguish bus, camion, trailer,...
In this paper, a single-mode Q-switched 980 nm Yb-doped fiber amplifier were studied experimentally. In the experiment, we used a 980 nm acousto-optics (AO) Q-switched Yb-doped single-mode fiber laser as the seed source, which generated an average output power of 73 mW at 980 nm with the pulse width of 10 ns at repetition frequency of 16 kHz. Then, another single-mode Yb-doped fiber pumped by a cw...
An all fiber front end was developed based on a 1064-nm DFB laser oscillator. The pulse was shaped by a waveguide amplitude modulator droved by a 10GS/s arbitrary waveform generator. Amplified by fiber amplifiers and Nd:YAG rod amplifiers, the signal was then frequency-converted to 532nm by temperature controlled LBO crystal with more than 10-mJ energy. Finally, the 532nm green laser was coupled to...
An useful design used for the dispersion compensation in Cr:LiSAF femtosecond lasers is reported. It is composed of 58 alternating Ta2O5 and SiO2 layers. The first part, from layer 1 to layer 45, which have quarter-wave optical thickness serve as high reflectivity dielectric stack. The second part, from layer 46 to layer 58, whose thicknesses are obtained by computer optimization provide constant...
A novel hybrid surface micromachined segmented mirror array is described. This device is capable of scaling to large apertures for correcting time-varying aberrations in laser applications . Each mirror is composed of bottom electrode, support part and mirror plate, in which a T type beam structure is used to support the mirror plate. It can provide mirror with the vertical movement and the rotation...
We optimize the performance of the hyperlens based on geometric parameters. The theoretical analysis and numerical simulation show that the dispersion relation of the hyperlens can be tuned by adjusting geometric parameters such as the metal filling ratio and number of alternating metal/dielectric layers. The metal filling ratio can be optimized to achieve 0° ray divergence. For the hyperlens with...
A three-dimensional (3D) scene is built up, and a camera array is used to simulate a micro-lens array to pick up the 3D scene in 3DS MAX software. Based on the principle of two step pickup method in computer generated integral imaging, the mathematical model of the secondary pickup is proposed, and the secondary integral image is synthesized using the proposed mathematical model. A vivid 3D scene...
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